3.9 quake near Borrego Springs jostles county

A magnitude 3.9 earthquake occurred at 12:32 p.m. Saturday about six miles east of Borrego Springs, apparently produced by the Coyote Creek fault, an extension of the highly active San Jacinto system, the US Geological Survey says. The quake began 3.8 miles deep, a common depth in Southern California. It's unclear whether Friday's 3.2 quake on the Elsinore fault, farther west, contributed to today's event. Seismologists closely study the San Jacinto and its extensions because the fault is capable of producing a catastrophic earthquake. The fault is also closer to the heavily populated areas of San Diego County than the better known San Andreas system.